All the cutters thus far mentioned are provided with central holes, and are intended to be mounted on an arbor which is carried by the milling machine spindle and supported in some suitable manner at the outboard end. There is an entirely different class of cutters, however, which are supported by the spindle only, and which are provided with teeth at the end of the cutter. These are known as end mills. They are made in a great variety of shapes and sizes, the ordinary end mill, Fig. 215, being cylindrical, with either a right- or left-hand spiral.
Fig. 215. Ordinary Form of End Mill Courtesy of Becker Milling Machine Company, Hyde Park, Massachusetts.
A special form of end mill for making T-slots is called the T-slot cutter, and is, in reality, a small side milling cutter carried by a small central stud, as shown in Fig. 216.
Fig. 216. T-Slot Milling Cutter and Section of Slot.
Fig. 217. Dovetail Milling Cutter.
Fig. 218. End Mill with Inserted Teeth.
Courtesy of Becker Milling Machine Company, Hyde Park, Massachusetts